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PR-18
Industrial RTD Probe with Aluminium Protection Head
Models In Stock
- Standard Size Aluminum protection head
- Class A accuracy conforming to IEC 60751
- Low temperature range: -50 to 250°C (-58 to 482°F)
- High temperature range: -50 to 450°C (-58 to 842°F)
PR-18
From
C$
151.71
Models In Stock
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Product Overview
- Accuracy Class A
- Enclosure Ratings IP67
- Nominal Resistance 100 Ω
- Nominal Resistance Note 100 Ω and 1000 Ω at 0°C standard; TCR = 0.00385 Ω/Ω/°C standard
- Number of Wires 3
- Probe Diameter 0.25 in
- Process Connection Size 1/2 in
- Process Connection Type NPT Male
- Protection Head NB3 Aluminum, Snap-Lock, Standard
- Series ID PR-18
- Sheath Material 316 Stainless Steel
- Shock IEC 60068-2-27; 50g/11ms (15 probes tested together) Duration: 1 day
- Temperature Coefficient 0.00385 Ω/Ω/°C standard
- Temperature Probe Style N/A
- Temperature Sensor Type RTD
- Vibration IEC 60068-2-6; 5 to 2000 Hz sweep rate, one active per minute; number of sweep cycles 10 and acceleration 5g (15 probes tested together) Duration: 1 day
Supported Applications
The Omega PR-18 series consists of industrial RTD probes featuring an aluminum protection head with a flip-top design. These sensors incorporate PT100 Ω or PT1000 platinum RTD elements and are designed for direct insertion into thermowells, tanks, vessels, and large pipes to measure flow material temperatures.
Operating Conditions & Performance
The series offers three distinct process temperature ranges depending on the model configuration: PR-18L (Low) covers -50 to 250°C (-58 to 482°F); PR-18H (High) spans -50 to 450°C (-58 to 842°F); and PR-18E (Extreme) operates from -200 to 600°C (-328 to 1112°F). Accuracy is rated Class A across the series, with specific ranges defined as Class A from -50 to 300°C (-58 to 572°F) or else Class B for PR-18H models, and Class A from -100 to 450°C (-148 to 842°F) or else Class B for PR-18E models. All variants utilize a standard TCR of 0.00385 Ω/Ω/°C.
Response time (T90) varies by sheath diameter and model series:
- PR-18L: 2.4 sec for 1/8", 2.8 sec for 3/16", and 3.25 sec for 1/4".
- PR-18H: 2.8 sec for 1/8", 4.11 sec for 3/16", and 5.41 sec for 1/4".
- PR-18E: 9 sec for 1/8", 9.8 sec for 3/16", and 10.6 sec for 1/4".
The probes feature an IP67 ingress protection rating, a sheath made of 316 stainless steel, and are rated for vibration per IEC 60068-2-6 (5 to 2000 Hz sweep rate, one active per minute; number of sweep cycles 10 and acceleration 5g) and shock per IEC 60068-2-27 (50g/11ms).
Configuration Options
The PR-18 series is configurable across several dimensions to meet specific installation requirements:
- Sensor Elements: Available with 100 Ω or 1000 Ω nominal resistance at 0°C.
- Diameters: Sheath diameters of 1/8, 3/16, and 1/4 inch are offered.
- Lengths: Standard probe lengths include 2, 3, 4, 6, 9, 12, 18, and 24 inches. Other lengths may be built using the Omega configurator.
- Process Connection: All models feature a 1/2" NPT thread for mounting into thermowells or direct process connections.
- Housing & Electricals: The aluminum protection head includes a screw terminal block for easy connection of insulated copper extension wire. A flip-top design facilitates access to the terminals.
Additional options include replacement probes (without the protection head assembly) and a spring-loading option, which allows the probe to bottom out in a thermowell for quicker response; however, this option should not be ordered unless a thermowell is used.
Key Product Differences
The series distinguishes itself through three primary model families based on temperature capability:
- PR-18L (Low): Designed for the -50 to 250°C (-58 to 482°F) range with Class A accuracy.
- PR-18H (High): Covers -50 to 450°C (-58 to 842°F), maintaining Class A accuracy from -50 to 300°C (-58 to 572°F) and reverting to Class B above that threshold.
- PR-18E (Extreme): Supports the widest range of -200 to 600°C (-328 to 1112°F), with Class A accuracy from -100 to 450°C (-148 to 842°F) and Class B outside that span.
While all models share the same aluminum protection head, IP67 rating, and 316 stainless steel sheath material, response times increase with higher temperature ranges due to differences in sensor construction or insulation requirements inherent to the PR-18H and PR-18E designs.
PDFs & Manuals
Show Ratings & Reviews
What is the recommended thermowell for this unit?
Thank you for your inquiry. We believe the best assistance would come from speaking to us directly at 888-826-6342 ask for the Temperature Department Mon. – Fri. (HOURS 8:30AM - 5:30PM EST).
Date published: 2025-10-03
Are the heads on these RTDs suitable for DIN Form B transmitter mounting? Aka, can you mount a hockey-puck transmitter inside of them?
Hello and thank you for this question.
Yes, you may use hockey-puck transmitters within the heads of these RTDs. The TX-12 is a perfect example of a transmitter that will fit and can be found though this link here https://www.omega.com/en-us/communication-and-connectivity/signal-conditioners-and-transmitters/signal-conditioners/p/TX12-Series
Date published: 2020-05-15
How can I tell if the RTD is spring loaded? Is the part number for PR-18E-3-100-1/4-18 spring loaded?
The PR-18E-3-100-1/4-18 is not spring-loaded. If the PR-18E-3-100-1/4-18 was spring loaded, at the end of the part number it would have the suffix -SL. For spring loaded probes, please click the Configure Now button to create a custom probe based on your specs.
Date published: 2025-10-03
What is the replacement RTD probe for this model if it is discontinued?
Thank you for your inquiry ElectricParts. The replacement probe for PR-18-2-100-1/4-6-E would be PR-18E-3-100-1/4-6. Here is the link: https://www.omega.com/en-us/temperature-measurement/temperature-probes/probes-with-industrial-heads/pr-18/p/PR-18E-3-100-1-4-6
Date published: 2022-01-27
Have a PR-18H-3-100-1/4-6 RTD probe with alum head. The termination head assembly sticks out too far. Is there a smaller head that can be assembled to the 1/2" NPT probe or a similar probe that I can interchange that has smaller head and 3/8 NPT thread?
Thank you for your inquiry. A smaller head that would be compatible with the PR-18H-3-100-1/4-6 RTD probe would be the NB2-2 head which is the miniature version of the one you currently have. Unfortunately, we do not offer the 3/8 NPT thread.
Date published: 2021-12-03